I would only hope to use that as a substitute for paid employment if you actually incorporate, give yourself a title, put your company on LinkedIn and otherwise treat it like a business. Noodling around on a side project that you might monetize eventually is not a substitute.
I disagree. Incorporating, giving yourself a title, and a LinkedIn page are things anyone can do. People who "play business" spend tons of time on this stuff, along with designing company logos, hiring accountants (for their zero revenue business), and lawyers (for NDAs to protect their non-existent idea.) I've seen it first hand. They'll do anything to avoid actual work: building and selling a product.
I suspect what Anon means is: if you plan to tell people your side project was your job, you should start treating it as your job.
I play around with some side projects where I don’t give a shit about user counts or GitHub stars or commercial viability, doing perhaps 4 hours work per week. If I told people this was me at the height of my powers, I’d expect them to be unimpressed.
Yes, exactly, I'm saying that what will matter to future employers is how much you treat the project as a job, and not the project itself, no matter how interesting or challenging it is from the technical side.
It won't matter as much as you think. They'll probably spend 5 minutes discussing it, if that. If you have a demo or something to show for your time, that will be a plus.
